1. Field of the Invention
The present invention relates to intake devices for outboard motors. More particularly, the present invention relates to an intake device that provides a good inertia charge effect in all speed ranges for an internal combustion engine of an outboard motor.
2. Description of the Related Art
Several factors affect the efficiency and effectiveness of delivering an air charge to an internal combustion engine. It has been found that at low-to-medium engine speeds, a relatively long intake pipe is desired to maximize engine performance. However, at high engine speeds, a relatively short intake pipe is best. It is known to provide an engine air intake system wherein the length of the intake pipes can effectively be lengthened based on engine speeds. An example of such a system is described in U.S. Pat. No. 6,736,100.
Certain other factors also arise in the design of engine air intake systems, especially intake systems for outboard motors. For example, in multi-cylinder engines, air intake into one cylinder may interfere with intake into another cylinder. Also, space constraints are particularly limiting for an outboard motor intake system, as the internal combustion engine and associated components must be enclosed within a cowling.